This fossilized feather dates back 66 million years to the late Cretaceous. It is, without a doubt, the best feather ever found from the age of dinosaurs, according to Jingmai O’Connor, an associate curator at the Field Museum of Natural History. In 2016, David DeMar was doing fieldwork in Montana’s Hell Creek Formation when he spotted a cherry-sized fossil. Embedded in a small crack on the surface was a tiny fossilized branching structure, marking the first fossilized feather found from that part of the world. Described in the journal Current Biology, the plume is part of an assortment that may reveal a late Cretaceous food web and shed light on why some ancient birds perished alongside dinosaurs after an asteroid impact while others survived to become modern birds. DeMar radioed his colleagues after discovering the nodule, and subsequent analysis confirmed it dated back to the late Cretaceous, right before the mass extinction event. O’Connor joined the project to determine what animal the feather belonged to and what it could reveal about evolution. The round object containing the feather was actually a chunk of coprolite, or fossilized feces, produced by a large meat-eating dinosaur like Tyrannosaurus rex or Nanotyrannus. CT-scanning revealed additional feathers, bone fragments, and two tiny fish scales inside the coprolite. O’Connor concluded they came from an ancient aquatic, swimming bird similar to a loon or grebe. Richard Prum, an ornithologist at Yale University, noted that the remarkable preservation—including evidence of individual cells—found within dinosaur poop was entirely unexpected. Researchers believe the fish scales were the remnants of the bird’s last meal before it was eaten by a predator like T. rex. While many types of birds went extinct following the Chicxulub asteroid impact and subsequent global cooling, one group survived to give rise to modern birds. O’Connor suggests that better insulation may have given the surviving birds an edge during the asteroid winter, noting that body feathers inside the coprolite lacked the insulation seen in modern counterparts. Other researchers, such as evolutionary biologist Julia Clarke of UT Austin, caution that it is a stretch to explain survivorship from incomplete fragments alone, though she praised the snapshot of a Cretaceous food chain. O’Connor believes the discovery opens a new way to access crucial soft-tissue specimens like fur and feathers preserved inside carnivorous dinosaur coprolites, helping researchers understand past extinctions and the current extinction crisis.
Source: npr.org
